A set of guidelines as support for the integrated geo-environmental characterization of highly contaminated coastal sites

The knowledge of geomorphodynamic aspects is crucial for understanding marine and coastal processes/dynamics as well as for characterizing coastal environments heavily affected by anthropogenic activities. To provide a framework of analysis that can be applied in a consistent way for the geo-environmental characterization of highly contaminated coastal sites, in this paper a set of operational guidelines is proposed. Special attention is given to the role of geomorphological-based surveys and analyses in defining (i) the site-specific geological model of the investigated site, (ii) the anthropogenic impacts on marine and coastal sediments, (iii) the expected morphodynamic variations induced by climate change and anthropogenic interventions, (iv) tailored dissemination activities and community engagement plans. Then, an evaluation of the state of the art of activities already performed for the characterization of the coastal contaminated sites located in the Apulia region (southern Italy) is provided. The outcomes of this research are also provided in the form of infographics to favor their dissemination among communities and stakeholders.


SEDIMENTOLOGICAL ANALYSIS VISUAL DESCRIPTION OF THE SAMPLES GRANULOMETRIC ANALYSIS MAGNETIC ANALYSIS RADIOGRAPHIC ANALYSIS
Sedimentological analyses allow to define stratigraphic, radiographic, and radiometric characteristics of the marine and coastal sampled sediments and to correlate seismic interpretations.

GEOELECTRIC AND HYDROGEOLOGICAL SURVEYS VERTICAL ELECTRICAL SOUNDING (VES) ELECTRICAL RESISTIVITY TOMOGRAPHY (ERT)
Geoelectric investigation (marine and terrestrial) allows to define the electrical resistivity of rocks and water bodies and, therefore, the main lithological discontinuities and the fresh-saltwater interface.

DEFINITION OF THE GEOLOGICAL MODEL ACQUISITION OF GEOLOGICAL DATA DERIVED FROM PREVIOUS CHARACTERIZATION ACTIVITIES, GEOPHYSICAL SURVEYS, AND ANALYSES. IN SITU GEOMORPHOLOGICAL SURVEYS AND CORE SAMPLING.
The site-specific geological model is used for the analysis of the different sedimentary units, the definition of their geometric relationships, the evaluation of the thickness of superficial deposits, and the spatial distribution of each sediment unit.Indirect geophysical surveys (seismic, acoustic, and geoelectric) allow to define over a wide area the main geological structures and their geometries within the stratigraphic succession.Direct analyses (sedimentological, geochemical, mineralogical, and biogeochemical) allow to define the lithostratigraphic characteristics of rock outcrops and marine substrate as well as the inorganic characteristics of sediments.

INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (ICP-MS) GAS CHROMATOGRAPHY MASS SPECTROMETRY (GC-MS; GC/MS-MS) FOURIER TRANSFORM INFRARED SPECTROSCOPY (FT-IR) RAMAN SPECTROSCOPY LASER INDUCED BREAKDOWN SPECTROSCOPY (LIBS) HYPERSPECTRAL IMAGING (HSI) ORGANIC CARBON CONTENT ANALYSIS
The assessment of pollutant concentrations in marine and coastal sediments and their comparison with limit values and sediment quality guidelines allows the level of contamination and related risk to be estimated.In addition, site-specific background values can be defined from the analysis of deeper sediment layers.

GEOPHYSICAL SURVEYS SINGLE/MULTI BEAM ECHO SOUNDER SURVEYS SIDE SCAN SONAR SURVEYS MAGNETOMETRIC SURVEYS
The interpretation of high-resolution morpho-bathymetric acoustic data allows the identification on the seabed of imprints and traces of anthropogenic activities.The acquisition of magnetometric data support the detection of buried structures and objects.

DEFINITION OF THE ANTHROPOGENIC ON MARINE AND COASTAL SEDIMENTS DESCRIPTION OF HISTORICAL AND CURRENT ANTHROPOGENIC ACTIVITIES CARRIED OUT IN THE SELECTED SIN. COLLECTION OF POLLUTION CHARACTERIZATION PLANS. SEDIMENT SAMPLING.
Marine and coastal sediments in highly contaminated coastal sites can be directly and indirectly impacted by anthropogenic activities.Direct impacts can be defined through geochemical analyses to estimate concentrations of organic and inorganic pollutants (including microplastics) in surface and sub-surface sediments.Indirect impacts, which include anthropogenic footprints on seabed morphology, the impact of maritime activities in areas (as shipping, fishing, and shellfish farming) and the dumping of litter and mega-litter, can be assessed through the interpretation of high-resolution geophysical data (i.e., acoustic and magnetometric surveys).

SEDIMENT SAMPLING GRAB SAMPLING (SURFICIAL SEDIMENTS) CORE SAMPLING (SURFICIAL, SUB-SURFICIAL, AND DEEP SEDIMENTS)
The identification of suitable sites for sediment sampling and the definition of the length of sediment cores to be taken are supported by information obtained from preliminary seismic surveys.
Innovative technologies allow to obtain high resolution bathymetric and topographic coastal models and to define submerged and emerged morphologies with high vertical accuracy and to assess their variation over time.

DEFINITION OF THE EXPECTED MORPHODYNAMIC VARIATIONS COLLECTION OF BATHYMETRIC AND TOPOGRAPHIC DATA ALREADY AVAILABLE AT THE NATIONAL AND REGIONAL SCALE FOR THE INVESTIGATED COASTAL SITES. HIGH-RESOLUTION TOPOGRAPHIC & BATHYMETRIC SURVEYS UNMANNED AERIAL VEHICLES (UAVS) SURVEYS TERRESTRIAL LASER SCANNER (TLS) SURVEYS OPTICAL TOTAL STATION SURVEYS SINGLE/MULTI BEAM ECHO SOUNDER
Ongoing climate-related changes in marine and atmospheric variables are expected to induce cascading effects on coastal physical processes (e.g., wave climate, currentsediment interactions, storm surges, erosion processes).Similarly, future coastal anthropogenic interventions may cause changes in longshore sediment transport.
The alteration of energy and mass balances generated by these processes may trigger contaminant mobilization mechanisms therefore the identification of geomorphodynamic interactions with the contamination features supports the sitespecific risk assessment procedure.The analysis of current shoreline displacements allows for an indirect assessment of the predominant site-specific morphodynamic conditions and thus the identification of coastal erosional focuses along the investigated SIN.The medium-term analysis is also used to obtain projections of future shoreline position.

MEDIUM AND SHORT-TERM SHORELINE OBSERVATIONS
The evaluation of the current variations in marine parameters (i.e., currents, waves, relative sea level) is performed by analysing historical data and current local observations obtained from the installation of monitoring instruments along the coastline.

OF COMMUNITY ENGAGEMENT PLANS AND ELICITATION OF STAKEHOLDERS FROM POTENTIALLY INTERESTED GROUPS TO ANY LEVEL OF ANALYSIS OF ALREADY CITIZEN SCIENCE PROGRAMS.
participatory stakeholder process lays the foundations for extensive citizens' participation in public processes resulting in the identification of collectively site-specific solutions the management of highly contaminated coastal sites.Stakeholders' engagement in participatory decision-making at the local and scale is fundamental for the definition of actions aimed at the reduction environmental and health risks.Furthermore, citizens can become active participants in the knowledge process by supporting the in-situ and real-time acquisition of information.
DISSEMINATION OF THE OBTAINED FROM THE DATA ANALYSIS ACTIVITIES.
Seismic reflection investigations are used in subsurface exploration to recognise the stratigraphic and structure of geological units.Marine acoustic investigations are used to obtain high-resolution morpho-bathymetric information.